Etching 3D Silicon for Optical Effect

Across the world researchers are working to create the next generation of electronics, and are hoping what they come up with is compatible with modern production techniques. This is to keep costs down and make it relatively easy for a company to adopt the new technology. Unfortunately there are some things the modern techniques cannot do, such as etching a 3D structure out of silicon, but researchers are working on that, and those at Karlsruhe Institute of Technology have succeeded in doing so for an optical device.

The optical device should be useful for processing optical signals used in telecommunications. To achieve this though it has to be manufactured with great precision, as it is the structure of the silicon that determines its optical properties. For that the researchers took a piece of silicon and applied a solution of polystyrene spheres just a micrometer wide to it. As the solution evaporated, the spheres self-assembled into a monolayer on the silicon. After adding a metal coating and removing the spheres, an etching mask is left on the silicon. Where ever the mask is missing, a plasma is be used to etch away the silicon, and with an electric field, the researchers can control what direction the plasma moves.

While the researchers developed this method to create this specific optical device, it can be used to produce other structures just by changing the mask. By freely manipulating the mask, it may be possible to manufacture some truly unique optical devices for telecommunications.